Control of scrambling sequence per symbol for digital post distortion

Abstract

Methods, systems, and devices for wireless communications are described. A transmitting device may select a scrambling sequence to use per symbol to reduce variance in a non-linearity parameter for a power amplifier (PA) output between a data symbol and a pilot symbol based on a PA model for at least one pilot symbol or one or more parameters of the model. The receiving device may indicate a capability to blindly estimate the scrambling sequence the transmitting device selected to the transmitting device. If the transmitting device does not receive the capability message from the receiving device or if the capability message indicates the receiving device is not capable of blind estimation, the transmitting device may indicate the selected scrambling sequence to the receiving device. Otherwise, the transmitting device may not indicate the selected scrambling sequence to the receiving device, and the receiving device may blindly estimate the scrambling sequence.

What is claimed is: 
     
       1. A method for wireless communications at a first wireless device, comprising:
 receiving, from a second wireless device, an indication of a capability of the second wireless device to blindly estimate a first scrambling sequence from a set of candidate scrambling sequences; 
 selecting the first scrambling sequence from the set of candidate scrambling sequences based at least in part on a value of a non-linearity parameter for a set of data resource elements for transmitting data in one or more symbol periods, a set of pilot resource elements for transmitting demodulation reference signals associated with the data in the one or more symbol periods, and the indication; 
 encoding the data for the set of data resource elements according to the first scrambling sequence; and 
 transmitting, in the one or more symbol periods, the set of data resource elements with the set of pilot resource elements. 
 
     
     
       2. The method of  claim 1 , further comprising:
 transmitting, to a second wireless device, control signaling indicating the first scrambling sequence. 
 
     
     
       3. The method of  claim 2 , wherein transmitting the control signaling comprises:
 transmitting a DCI message comprising one or more bits indicating the first scrambling sequence, wherein the second wireless device is a user equipment (UE). 
 
     
     
       4. The method of  claim 2 , wherein transmitting the control signaling comprises:
 transmitting an UCI message comprising one or more bits indicating the first scrambling sequence, wherein the second wireless device is a base station. 
 
     
     
       5. The method of  claim 1 , further comprising:
 performing, for each set of one or more symbol periods, an estimation procedure to evaluate the non-linearity parameter corresponding to each scrambling sequence from the set of candidate scrambling sequences for the one or more symbol periods; and 
 identifying the first scrambling sequence based at least in part on performing the estimation procedure. 
 
     
     
       6. The method of  claim 5 , wherein performing the estimation procedure comprises:
 determining, for each set of one or more symbol periods, a plurality of peak-to-average power ratios corresponding to the set of candidate scrambling sequences; and 
 selecting the first scrambling sequence based at least in part on comparing the plurality of peak-to-average power ratios corresponding to the set of candidate scrambling sequences. 
 
     
     
       7. The method of  claim 6 , wherein a first peak-to-average-power ratio of the first scrambling sequence is a lowest value of the plurality of peak-to-average power ratios. 
     
     
       8. The method of  claim 1 , wherein selecting the first scrambling sequence from the set of candidate scrambling sequences is performed once per group of symbol periods. 
     
     
       9. The method of  claim 8 , wherein the group of symbol periods comprises one slot. 
     
     
       10. The method of  claim 1 , wherein a peak-to-average-power ratio for the data from each of the one or more symbol periods encoded according to the first scrambling sequence satisfies a threshold value or is a minimum value for the peak-to-average-power ratio among a set of peak-to-average-power ratios. 
     
     
       11. The method of  claim 1 , wherein selecting the first scrambling sequence is based at least in part on a modulation order of the set of data resource elements having a number of points that satisfies a threshold number of points. 
     
     
       12. A method for wireless communications at a second wireless device, comprising:
 transmitting, to a first wireless device, an indication of a capability of the second wireless device to blindly estimate a first scrambling sequence from a set of candidate scrambling sequences; 
 receiving, from the first wireless device, a set of data resource elements in one or more symbol periods, the set of data resource elements comprising data and a set of pilot resource elements comprising demodulation reference signals associated with the data in the one or more symbol periods; 
 estimating, from the set of candidate scrambling sequences, the first scrambling sequence used by the first wireless device to scramble the data; and 
 decoding the data of the set of data resource elements according to the first scrambling sequence. 
 
     
     
       13. The method of  claim 12 , wherein identifying the first scrambling sequence comprises:
 receiving, from the first wireless device, control signaling indicating the first scrambling sequence. 
 
     
     
       14. The method of  claim 13 , wherein receiving the control signaling comprises:
 receiving a DCI message comprising one or more bits indicating the first scrambling sequence, wherein the first wireless device is a base station. 
 
     
     
       15. The method of  claim 13 , wherein receiving the control signaling comprises:
 receiving an UCI message comprising one or more bits indicating the first scrambling sequence, wherein the first wireless device is a user equipment (UE). 
 
     
     
       16. The method of  claim 12 , further comprising:
 performing a measurement of a channel corresponding to the set of data resource elements, 
 wherein the first scrambling sequence is estimated based at least in part on the measurement of the channel. 
 
     
     
       17. The method of  claim 12 , wherein the first scrambling sequence is used to decode the data for one group of symbol periods. 
     
     
       18. The method of  claim 17 , wherein the group of symbol periods comprises one slot. 
     
     
       19. The method of  claim 12 , wherein a peak-to-average-power ratio for the data from each of the one or more symbol periods satisfies a threshold value or is a minimum value for the peak-to-average-power ratio among a set of peak-to-average-power ratios. 
     
     
       20. The method of  claim 12 , wherein identifying the first scrambling sequence is based at least in part on a modulation order of the set of data resource elements having a number of points that satisfies a threshold number of points. 
     
     
       21. A first wireless device for wireless communications, comprising:
 one or more memories storing processor-executable code; and 
 one or more processors coupled with the one or more memories and individually or collectively operable to execute the code 
 to cause the first wireless device to:
 receive, from a second wireless device, an indication of a capability of the second wireless device to blindly estimate a first scrambling sequence from a set of candidate scrambling sequences; 
 select the first scrambling sequence from the set of candidate scrambling sequences based at least in part on a value of a non-linearity parameter for a set of data resource elements for transmitting data in one or more symbol periods, a set of pilot resource elements for transmitting demodulation reference signals associated with the data in the one or more symbol periods, and the indication; 
 encode the data for the set of data resource elements according to the first scrambling sequence; and 
 transmit, in the one or more symbol periods, the set of data resource elements with the set of pilot resource elements. 
 
 
     
     
       22. The first wireless device of  claim 21 , wherein the one or more processors are individually or collectively operable to execute the code to cause the first wireless device to:
 transmit, to a second wireless device, control signaling indicating the first scrambling sequence. 
 
     
     
       23. The first wireless device of  claim 21 , wherein the one or more processors are individually or collectively operable to execute the code to cause the first wireless device to:
 perform, for each set of one or more symbol periods, an estimation procedure to evaluate the non-linearity parameter corresponding to each scrambling sequence from the set of candidate scrambling sequences for the one or more symbol periods; and 
 identify the first scrambling sequence based at least in part on performing the estimation procedure. 
 
     
     
       24. A second wireless device for wireless communications, comprising:
 one or more memories storing processor-executable code; and 
 one or more processors coupled with the one or more memories and individually or collectively operable to execute the code 
 to cause the second wireless device to:
 transmit, to a first wireless device, an indication of a capability of the second wireless device to blindly estimate a first scrambling sequence from a set of candidate scrambling sequences; 
 receive, from the first wireless device, a set of data resource elements in one or more symbol periods, the set of data resource elements comprising data and a set of pilot resource elements comprising demodulation reference signals associated with the data in the one or more symbol periods; 
 estimate, from the set of candidate scrambling sequences, the first scrambling sequence used by the first wireless device to scramble the data; and 
 
 decode the data of the set of data resource elements according to the first scrambling sequence. 
 
     
     
       25. The second wireless device of  claim 24 , wherein, to identify the first scrambling sequence, the one or more processors are individually or collectively operable to execute the code to cause the first wireless device to:
 receive, from the first wireless device, control signaling indicating the first scrambling sequence. 
 
     
     
       26. The second wireless device of  claim 24 , wherein the one or more processors are individually or collectively operable to execute the code to cause the second wireless device to:
 perform a measurement of a channel corresponding to the set of data resource elements, 
 wherein the first scrambling sequence is estimated based at least in part on the measurement of the channel and the capability.